The Schneider Optics 21-1071606 is a 28mm 5 megapixel F-LD mount lens with a M62 x 0.75 filter size, -0.03% distortion.

EMERALD lenses are ultra-low distortion lenses with an image circle diameter of 43.2 mm, featuring a compact, robust design, locking focus and iris. They are designed for close up range or infinity and optimized for a uniform image quality over the whole sensor area. The 400-1000 nm broadband coating makes them suitable for applications in the visible and the near infrared spectrum. EMERALD lenses are available in F-S and F-L variants. The F-SD version is suitable for "close up" finite working distances typical of machine vision applications. The F-LD version is optimized for long working distances out to Infinity.